Oil and method for stabilizing same



Patented Mar. 23,

Sidney Masher, New York, N.

Y., assignor to Masher Foundation, Incorporated, New York, N. Y., a corporation of New York No Drawing. Ap

plication July 31, 1940,

Serial No. 348,826 9 Claims. (Cuzco-398.5)

relates to the stabilization of glyceride oils and particularly to the stabiliaation against oxidative deterioration of those glyceride oils which contain a large proportion of unsaturated glycerides.

It has been found that these oils are particularly oxldizable and that this deterioration is increased wherever the oils are subjected to high temperature deodorization during the refining process.

It has now been found that when such glyceride oils are heated to relatively high temperatures with combinations of phosphorus compounds and particularly phosphatides, phosphoproteins or phospholipins such as lecithin and cephalin or phosphoric acid or its salts on the one hand together with an aromatic compound, preferably at The present invention least di-substituted with amino or hydroxy groups on the other hand, instead of losing stability and becoming more subject to deterioration, the oils will become very stable and highly resistant to oxidative deterioration and rancidity.

The phosphorus compounds and the aromatic compounds are used preferably in equal proportions. They may also be employed in relative proportions varying from about 1 part of the former and 10 parts of the latter to 10 parts of the former and 1 part of the latter and the combinations are dispersed in the glyceride oil which is then heated or they may be added to the oil during high heat treatment to develop marked anti oxygenic efiectiveness.

These phosphorus and aromatic compounds may be added separately to the oil to be stabilized or may first be added to the oil but in either case they are thoroughly dispersed in the oil and held dispersed in the oil while the oil is at an elevated temperature in excess of 250 F. and preferably at over 400 F.

The preferred aromatic compounds which are combined with the lecithin or phosphatide have desirably a poly-substituted benzene ring excluding such compounds as phenol or aniline. These compounds are the dihydroxy benzenes, the diamino benzenes, the aminohydroxy benzenes and less preferably similar compounds in which the other substituents in addition to the amino or hydroxy group are the alkyl or aryl group such as aryl phenol or an alkyl aniline or even a second nuclear chain such as,. for example, as in the case of an alpha or beta naphthol or an alpha or beta naphthylamine or aminonaphthols, or diamino or dihydroxy naphthalenes.

The preferred aromatic hydroxy compound to use in accordance with this invention is hydromixed in combination and then molt-(v) where :n is at least one OH and preferably includes two OH groups or even alkoxy groups and may less preferably include Nm or COOH or CHO or CO or alkyl chains including the same; where n is at least 2; and where y is hydrogen, aryl, alkoxyl, aralkyl, alpharyl, amino, sulpho, aldo, keto or alkyl chains or groups including the same.

As examples of the less preferred compounds included in the classification given above are diphenylamine, alphanaphthylamine, phenylbetanaphthylamine, eugenol, gallic acid and gallotan- Among the other compounds which may also be utilized are ethyl, propyl, butyl, amyl, hexyl, or octyl phenols, anilines, naphthols, hydroquinones, pyrogallols or the methoxy, ethoxy, butoxy ethers, dihydroxy or di-amino or hydroxy amino naphthalenes, which alkyl groups may or may not be substituted by aryl groups such as phenyl or toluyl such as ethyl, butyl, amyl, hexyl or octyl. Less preferably, it is possible to utilize aryl substituted phenols, anilines, naphthols, naphthylamines, hydroquinones, -aminophenols, cresols or xylenols.

Among the other compounds that may be especially employed are included polyhydroxybenzenes in which one of the hydroxy groups may be etherified such as hydroxyhydroquinone, 1:2:4 trihydroxybenzene, l :2 di-methy1-3 G-di-hydroxy benzene, 1 2-di-methy1-4 5-di-hydroxy benzene, l 3-di-ethy1-2 5-di-hydroxybenzene, ethyl pyrogallol, methoxy hydroquinone, pyrogallol-lmethyl ether, ethoxy catechol, or naphthols such as 1:2-di-hydroxy naphthalene, 1:4 di-hydroxy naphthalene, or poly aminobenzenes or aminophenols or aminonaphthols such as di or triamino benzenes, 1:5 dihydroxy naphthalene, para-phenylene-di-amine, ortho-aminophenol, para-aminophenol, dimethyl para-aminophenol, di-butyl aminophenol, (ii-ethyl aminocresol, phenyl-aminophenol, benzyl aminophenol, 2 amino-fi-hydroxy-toluene, benzyl-p-aminophenol, dibenzyl-p-amino phenol, 2:4 diamino 'di Other useful diand tri-hydroxy comphenylamine, D.n-diamino-diphenyl amine, phenyl alpha naphthylamine, alkyl alpha naphthylamine, or less preferably other substituted benzenes such as carvacrol, tribromo or trichloro phenols, etc., or other compounds such as furfural or p-hydroxy phenyl morpholine.

The preferred combination of phosphatide and aromatic compound is a mixture of lecithin and hydroquinone, preferably in equal proportions by weight.

The lecithin may be obtained from any source but is preferably obtained from crude soya bean, corn or cottonseed oil by precipitation of the lecithin after expulsion or extraction of the oil from the soya beans, corn germs or cottonseed.

The lecithin may be in its crude form or in substantially refined form when utilized for combination with hydroquinone and for dispersal in the oil at the elevated temperature to produce the stabilizing eifect.

Instead of using the phosphorus compound such as the lecithin in substantially purified condition, it is also possible to use animal or vegetable materials which are high in phosphatide content and which contain 30% to 40% or more total phosphatide content against their solids weight, such as, for example, nerve tissue and brain tissue.

The combination is added in an amount of less than 5% and desirably less than 1%. As little as 0.005% to 0.1% will give highly desirable stabilizing results when the glyceride oils are treated in accordance with this invention.

After dispersing the combination of phosphatide and aromatic compound, such as the combination of lecithin and hydroquinone in the oil, the oil is heated to an elevated temperature, desirably in excess of 250 F. and preferably to between 325 F. and 450 F. for at least to 30 seconds.

It has been found that merely melting a glyceride fat or oil, particularly where the glyceride is solid at room temperature, is not suficient to give the desired effect and it is necessary to utilize an elevated temperature substantially above the melting point of the glyceride if it normally be solid at room temperature.

During the heating period, any residue which may become burnt or charred may be removed as by filtration or centrifuging from the body of the oil, as the stabilization of the oil will already have been effected.

The oil which has been heated with the combination will normally be darker as the result of the elevated temperature treatment. It, however, has been found that the original light colorof the oil may be restored by a bleaching process as, for example, with fullers earth or other decolorizing materials and still retaining a substantial enhancement in the stability of the oil.

The results of the present invention are particularly surprising since antioxidants are recognized as losing at least a portion of, and in most cases a major portion of their effectiveness when heated to elevated temperatures such as to 400 F. or more.

Example I Bleached refined lard was treated by adding thereto and therein 0.05% of a' combina-- tion of equal parts by weight of hydroquinone and soya lecithin. The lard containing the combination was then heated to 400 F. for 30 seconds and allowed to cool. The lard was thereupon tested by bubbling air through a cc.

ing results.

Rancid after, hours above combinal0 Untreated lard Lard containing 0.05% of the tion unheate Lard containing 0.05% of the above combination heated to 400 F. for 30 seconds and allowed to co Example II The following experiments are exemplary of the stabilizing activity of a variety or organic 20 compounds used in combination with phosphatides. The combinations given below were added to and thoroughly dispersed in the lard. In the first column the lard containing the combination was not heated whereas in the second column the lard containing the added materials was heated to 400 F. for 10 minutes and allowed tc cool. In both columns th lard was then maintained at 125 F. until rancidity was observed the hours given indicating the length of tim; elapsing before rancidity developed at 125 F. and

therefore the stability of the lard at 125 F.

Heated to Unheatod 400 F. for lominntcs Lard containing 0.1% lecithin plus- Hem Hours 0.05% hydroquinona 121 605 0.02 ahenylbetanaphthylamine. 27 68 0.01 alphanaphtho 32 79 0.002% benzylaminophenol i4 63 When combinations of these materials are added to oils and thoroughly dispersed in them and said oils are then heated to above 250 F. and more desirably from a temperature of 325 F. to 500 F. whereby they are frequently charred or burnt in the oils, an unusually high protection against oxidation is obtained.

Example III The following combination was prepared and tested in lard as in Example If.

Heated to 400 F. for 10 minutes Unheated Lard containing 0.1% phosphoric acid plus Hours I Hours 0.1% hydroquinone 212 470 used as a base for addition too, large body of oil. The most desirable method is for the combination to be dispersed in the entire body of material to be stabilized, followed by subjecting the oil to a high heat in order to produce the desired interaction or result.

Apparently a chemical reaction occurs between the components of the combination and the oil bilization is effected,

at the elevated temperature whereby the staas this reaction does not appear to berelatedto ordinary negative oxidation catalysis by means of which antioxidants normally exercise activity.

The higher the temperature to which the oil containing the combination of,.for example, hydroquinone and lecithin, is subjected, the greater the stabilizing action although the sharpest increase in stabilization is between about 325 F. and 450 F.

The heat treatments need not be prolonged, I

the enhanced antioxygenic effect being obtained in relatively short periods particularly where the I higher temperatures are employed. Normally, the oil containing the combinations may-merely be heated to the desired temperature and allowed to cool, being held at the high temperature for a period of 10 minutes or more.

The heat treatment at atmospheric pressure sub-atmospheric pressures with satisfactory results.

This process may be utilized in the treatment and stabilization of a wide variety of refined or but the use of super or may also be employed will usually be carriedout crude glyceride oils such as the vegetableoils and fats including cottonseed oil, corn oil, peanut oil, linseed oil, soya bean oil, olive oil, etc., the animal oils and fats including lard, tallow, oleo oil, cod liver oil, halibut liver oil, mackerel oil, menhaden oil, herring .oil, shark liver oil, butter, etc., the glyceride soap oils and the sulfonated oils.

Not only is the oil stabilized, but components of the oils are also stabilized. For example, the vitamin A content of fish liver oil and other oils, the carotene of butter fat and similar substances associated with the oils which may be destroyed or reduced by oxidation are highly stabilized by this treatment.

This invention is, however, particularly beneficial in the treatment of thos glycerides which contain large proportions of unsaturated fatty acids, as the combinations appear to react more completely with these unsaturated oils at the elevated temperatures.

Although the component parts of the combinations or the combinations themselves may already have some antioxygenie effect when added to the glyceride oils and without the heat treatment, nevertheless such antioxidant powder is very greatly increased and enhanced by heating the combination in the oil to over 250 F. and preferably to 325 F. to 450 F.

The stability of the treated oils will often be enhanced from to 500% or more by the heat treatment in the presence of these combinations as compared to the stability which would be obtained by the addition of the combinations without the heat treatment described in this invention.

The most important features of the present invention reside in the fact that the added materials are not normally present in the oil to be stabilized and upon addition are thoroughly dispersed in such oil. The heat treatment is out for 'a sufficient length of time to increase the stability by usually not less than 50% over the stability of the unheated oil.

While the combination is dispersed in the oil at the elevated temperature of, say 400 F., superheated steam may, where desired, be continuously injected into the oil over a period as long as 4 to 6 hours and the objectionable flavors and odors originally present in the oil may be recarried Apparently a further moved therefrom while the combination is exerting its enhanced antioxygenic effect.

It has been found particularly desirable for a small amount of the combination to be added to high fat containing animal products, heating at atmospheric peratures of about 250 F. so that the glyceride oil or fat contained therein is released from the meat or fish animal product and a highly stabilized animal glyceride is obtained.

For example, to a kettle of hog fat containing total glycerides may be added 0.02% of a combination of hydroquinone and lecithin against the weight of the hog fat and the combination placed'in a. steam kettle with steam being injected into the kettle to produce about 45 pounds pressure. After a 4 to 6 hour treatment, the pressure may be released and the rendered lard removed. The stability of the lard obtained in this manner will be much greater than if the combination had merely been added to the lard after rendering.

For example, when a small amount of a combination of gum guaiac and lecithin is added to hog fat and the hog fat containing the combination is then rendered at a temperature of 275 F. for 4 hours, the rendered lard removed from the rendering kettle has a far greater stability than where a proportionate amount of the combination is added to the lard after rendering and the improvement in stability is even greater than where the combination is added to the lard after rendering and the lard containing the combination is then heated to 275 F. for 4 hours. interaction takes place by adding the combination to the rendering kettle where the rendering is conducted at over 250 F. resulting in a most highly stabilized oil.

In a similar manner, a small amount. of the combination may be added to the rendering kettle in the rendering of other meat and fish oils and fats including tallow, menhaden oil, herring oil, etc., or to the cooking kettles in the manufacture of fish meals, particularly high glyceride containing fish meals, and where the temperature is at least about 250 F., the desired interaction will result produeing enhanced stabilization. i Where the glyceride oils are heated over long periods to temperatures over 250 F. and desirably to temperatures over 300 F., small amounts of the combination may be added to the oils at regular intervals of 5 to 20 hours. In this manner, the glycerides will be held in highly stabilized and non-rancid condition over very long periods.

In addition to treating the glyceride oils and fats with these combinations, the essential oils such as lemon oil and orange oil may similarly be treated with the combinations followed by an elevated temperature treatment to enhance the antioxygenic effect.

The combinations also exert an enhanced antioxygenic effect when added in small proportions to the substantially non-volatile, high molecular weight, hydrocarbon oils and particularly the lubricating oils followed by temperature or elevated pressures to temsion of the atmosphere or without contact air.

It is'moreover desirable for the combination to be maintained in dispersed condition during the heat treatment and so that it will not tend to settle or conglomerate or be present in the form of large lumps or particles since in the latter case the fully desirable results of the present invention are not obtained.

It is desirable that the oil after treatment in accordance with the present invention will not be materially changed in its odor or flavor. The oil will, however, have a darker color which'may be removed by subjecting it to a bleaching operation.

It has also been found that desirable results are obtained where the combination is mixed with the oil or fibrous materials containing the glyceride oil and then the oil is heated to a temperature of, say from 250 F. to 500 F. under a reduced pressure, such as under a gas pressure less than 1 pound per square inch, to cause distillation of part or all of the glyceride oil composition and it has been observed that such distilled fraction is highly stable and is also free of the combination which has served as the stabilizing agent at the elevated temperature of distillation.

After treatment of the glyceride oil with the combination at the elevated temperature, the unsaponifiable fraction may be removed as by alcoholic extraction and said unsaponii'iable fraction utilized for addition to other oxidizable oils to protect them against oxidative deterioration.

Combinations of lecithin or other phosphatide and hydroxylamine may also be employed for addition to the oils followed by the heat treatment to over 250 F. as may also be'employed the reaction product of lecithin andhydroxylamine.

The present application is acontinuation in part of application Serial No. 247,631, filed December 24, 1938; Serial No. 292,613, filed August 30, 1939, now Patent 2,198,208; Serial No. 260,898, filed March 10, 1939, now Patent 2,198,211; and Serial No. 304,945, filed November 1'7, 1938, now Patent 2,216,711.

Having described my invention, what I claim is:

1. A process of stabilizing glyceride oils subject to oxidative deterioration whereby they become less subject to such deterioration, which comprises adding thereto and dispersing there in a small amount of a phosphorous compound selected from the group consisting of the phosphatides, phosphoproteins, phospholipins, phosphoric acid and the salts of phosphoric acid and a small amount of a compound having the general formula m(z)n(yl where x is a radical selected from the group consisting of OH, alkoxy, N'Hz, COOI-I, CHO, CO and alkyl chains including the same, where n is at least 2 and where y is a radical selected from the group consisting of hydrogen, aryl, alkoxyl, aralkyl, alpharyl, amino, sulpho, aldo, keto and alkyl chains including the same, and heating to in excess of 250 F. a

2. A process of stabilizing glyceride oils subject to oxidative deterioration whereby they bewith come'less subject to such deterioration, which comprises adding thereto and dispersing therein a small amount of a phosphorous compound selected from the group consisting of the phosphatides, phosphoproteins, phospholipins, phosphoric acid and the salts oi phosphoric acid and a small amount 01' a polyhydroxy aromatic compound, and heating to in excess of 250 F. while the oil is under sub-atmospheric pressure.

3. A process of stabilizing glyceride oils subject to oxidative deterioration whereby they become less subject to such deterioration, which comprises adding thereto and dispersing therein a small amount of a combination oi a phosphatide i and a polyhydroxy benzene, and heating to in excess of 250 F.

4. A process of stabilizing glyceride oils subject to oxidative deterioration whereby they become less subject to such deterioration, which said aromatic compound having the general comprises adding thereto and dispersing therein a small amount of a combination of lecithin and hydroquinone, and heating to in excess of 250 F.

5. A process of stabilizing glyceride oils subject to oxidative deterioration whereby they become less subject to such deterioration, which comprises adding thereto and dispersing therein a small amount of a combination of a phosphatide and an aminohydroxy aromatic compound, and heating to in excess of 250 F.

6. A process of stabilizing glyceride oils subject to oxidative deterioration whereby they become less subject to such deterioration, which comprises adding thereto and dispersing therein a small amount of a combination of a phosphatide and an aminohydroxy benzene, and heating to in excess of 250 F.

7. A glyceride oil normally subject to oxidative deterioration carrying the reaction product of a phosphorous compound and an aromatic compound in the oil, said phosphorous compound selected from the group consisting of the phosphatides, phosphoproteins, phospholipins, phosphoric acid and the salts of phosphoric acid,

formula compound selected from the group consisting of the phosphatides, phosphoproteins, phospholipins, phosphoric acid and the salts of phosphoric acid, said aromatic compound having the general formula excess of 250 F. whereby an enhanced antioxy- 10 genie effect is obtained.

9. A glyceride oil normally subject to oxidative deterioration carrying the reaction product of a phosphatide and a polyhydroxy benzene in the 011, said reaction product having been formed by heating the combination in the oil to a temperature in excess of 250 F. whereby an enhanced antioxygenic effect is obtained.

SIDNEY MUSHER. 

